Door closer and piston thereof

Abstract

The piston comprises a piston body of a cylindrical structure, a roller groove is formed in the end face of one side of the piston body in a concave mode, a roller is rotatably arranged in the roller groove and comprises a rotating shaft and an outer ring, the rotating shaft is sleeved with the outer ring in a rolling mode, and the outer ring is of an annular structure; a plurality of roller pins are arranged between the inner wall of the outer ring and the rotating shaft, and the two ends of the inner wall of the outer ring protrude to form annular limiting bosses respectively. The door closer and the piston thereof are simple in structure, the limiting boss limits the axial movement of the roller pin, and the service life is prolonged.

Description

Technical Field

[0001] This application relates to the field of door closer technology, and in particular to a door closer and its piston. Background Technology

[0002] Door closers, as essential facilities in modern buildings, are widely used in various sectors of society. With continuous social development and progress, national requirements for fire protection and security are becoming increasingly stringent, necessitating the installation of door closers on many passageway doors and fire doors. Currently, the main types of door closers on the market are hydraulic and electric. (See also...) Figure 3 As shown, during the opening / closing process of the hydraulic door closer, the camshaft 6 rotates and compresses the piston. A roller is installed at the end of the piston near the camshaft 6 to avoid interfering with the free rotation of the camshaft 6. The roller is typically composed of a shaft, needle rollers, washers, and an outer ring. During use, the needle rollers may experience axial movement, acting on the washers and causing them to break. This can prevent the rollers from rotating, and the resulting fragments can enter the hydraulic oil, causing blockages in the oil passages. Therefore, improvements are needed. Utility Model Content

[0003] The purpose of this invention is to provide a door closer and its piston to overcome the shortcomings of the prior art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] This utility model discloses a piston, including a cylindrical piston body. A roller groove is recessed on one end face of the piston body, and a roller is rotatably disposed in the roller groove. The roller includes a rotating shaft and an outer ring that is rolled and sleeved on the rotating shaft. The outer ring has an annular structure, and a plurality of needle rollers are disposed between its inner wall and the rotating shaft. Annular limiting bosses protrude from both ends of the inner wall of the outer ring. The gap between two limiting bosses is greater than the length of the needle rollers. The inner diameter of the limiting bosses is greater than the diameter of the rotating shaft and less than the sum of the diameter of the rotating shaft and twice the diameter of the needle rollers.

[0006] Furthermore, in the piston described above, inclined surfaces are respectively provided on the outer sides of both ends of the outer ring.

[0007] Furthermore, in the piston described above, a clearance groove is provided at the connection between the limiting boss and the inner wall of the outer ring.

[0008] Furthermore, in the piston described above, washers are provided at both ends of the needle roller, and the washers are rotatably sleeved on the rotating shaft.

[0009] Furthermore, in the piston described above, the outer diameter of the washer does not exceed the inner diameter of the limiting boss.

[0010] Furthermore, in the piston described above, the thickness of the washer is less than the thickness of the limiting boss.

[0011] Furthermore, in the piston described above, a flow channel communicating with the roller groove is provided along its axial direction within the piston body.

[0012] Furthermore, in the piston described above, an annular sealing groove is recessed on the circumferential surface of the piston body.

[0013] This utility model also discloses a door closer, including the piston described above.

[0014] Compared with the prior art, the door closer and its piston structure of this utility model are simple. The limiting boss restricts the axial movement of the needle roller, and the needle roller cannot act on the piston body, thus avoiding damage to the gasket and extending the service life of the door closer and its piston. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 The diagram shown is a schematic representation of the piston in a specific embodiment of this utility model.

[0017] Figure 2 The figure shown is a cross-sectional view of the piston with the washer omitted in a specific embodiment of this utility model.

[0018] Figure 3 The diagram shown is a schematic of the structure in the prior art where the camshaft acts on the piston. Detailed Implementation

[0019] The technical solutions of the present utility model will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] Combination Figure 1 and Figure 2As shown, a piston includes a cylindrical piston body 1. A roller groove is recessed on one end face of the piston body 1, and a roller is rotatably disposed in the roller groove. The roller includes a rotating shaft 2 and an outer ring 3 that is rolled and sleeved on the rotating shaft 2. The outer ring 3 has an annular structure, and a plurality of needle rollers 4 are disposed between its inner wall and the rotating shaft 2. Annular limiting bosses 31 protrude from both ends of the inner wall of the outer ring 3. The gap between the two limiting bosses 31 is greater than the length of the needle rollers 4. The inner diameter of the limiting bosses 31 is greater than the diameter of the rotating shaft 2 and less than the sum of the diameter of the rotating shaft 2 and twice the diameter of the needle rollers 4.

[0021] In this technical solution, a U-shaped opening groove is recessed on one side end of the piston body to serve as a roller groove. The two side walls of the roller groove are respectively provided with U-shaped grooves / through holes corresponding to the rotating shaft, which can accommodate the rotation of the roller shaft. The limiting boss restricts the axial movement of the needle roller, and the needle roller cannot act on the piston body, thereby extending the service life of the door closer and its piston.

[0022] For example, combined Figure 1 and Figure 2 As shown, inclined surfaces are provided on the outer sides of both ends of the outer ring 3.

[0023] In this technical solution, the outer ring is made of GCr15 steel (high carbon chromium bearing steel). After processing, it is quenched and tempered, and its hardness can reach HRC56~60. It has excellent wear resistance, high contact fatigue strength and good dimensional stability. The outer ring has beveled surfaces on both sides of the axial ends to reduce the contact area with the inner wall of the roller groove.

[0024] For example, combined Figure 1 and Figure 2 As shown, a clearance groove 32 is provided at the connection between the limiting boss 31 and the inner wall of the outer ring 3.

[0025] In this technical solution, the clearance groove serves as a relief groove for machining such as grinding the inner wall of the outer ring, which facilitates machining. At the same time, the clearance groove can prevent contact between the inner wall of the outer ring and the chamfered parts at both ends of the needle roller, reducing the possibility of the needle roller and the inner wall of the outer ring getting stuck.

[0026] For example, combined Figure 1 As shown, washers 5 are provided at both ends of the needle roller 4, and the washers 5 are rotatably sleeved on the rotating shaft 2.

[0027] In this technical solution, the needle rollers are made of SKF3 alloy steel and undergo carbonitriding and tempering treatments to achieve a hardness of HRC59-64. A tungsten carbide coating is also applied to their surface to further improve the hardness and wear resistance of the needle rollers. The washers are made of 65Mn steel and undergo quenching treatment to achieve a hardness of HRC57-60. The washers reduce the possibility of foreign matter entering between the outer ring and the needle rollers, between the needle rollers, and between the needle rollers and the shaft, ensuring smooth rotation of the rollers.

[0028] For example, combined Figure 1 As shown, the outer diameter of the washer 5 does not exceed the inner diameter of the limiting boss 31.

[0029] For example, combined Figure 1 As shown, the thickness of washer 5 is less than the thickness of limiting boss 31.

[0030] In both of the above technical solutions, the gasket will not be squeezed between the outer ring and the inner wall of the roller groove, between the needle roller and the limiting boss, or between the needle roller and the inner wall of the roller groove, thus avoiding gasket damage and extending the service life of the door closer and its piston.

[0031] For example, combined Figure 1 As shown, a flow channel connecting to the roller groove is provided inside the piston body 1 along its axial direction.

[0032] In this technical solution, the flow channel is used to install valves such as pressure relief valves / check valves. The specific structure and principle are existing technologies and will not be described in detail here.

[0033] For example, combined Figure 1 and Figure 2 As shown, the piston body 1 has an annular sealing groove recessed on its circumferential surface.

[0034] In this technical solution, the sealing groove is used to install conventional sealing rings to improve the sealing between the piston body and the door closer housing. The piston body has a limiting groove corresponding to the door closer spring on the side face away from the roller to avoid failure caused by spring tilting.

[0035] A door closer includes a housing, in which the piston is slidably disposed. A limiting boss restricts the axial movement of the needle roller, preventing the needle roller from acting on the piston body, thus avoiding damage to the gasket and extending its service life, thereby extending the service life of the door closer.

[0036] In summary, the door closer and its piston structure of this utility model are simple. The limiting boss restricts the axial movement of the needle roller, and the needle roller cannot act on the piston body, thus avoiding damage to the gasket and extending the service life of the door closer and its piston.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A piston, characterized in that, The piston body includes a cylindrical structure. A roller groove is recessed on one end face of the piston body. A roller is rotatably disposed in the roller groove. The roller includes a rotating shaft and an outer ring that is rolled around the rotating shaft. The outer ring has an annular structure, and a plurality of needle rollers are disposed between its inner wall and the rotating shaft. Annular limiting bosses protrude from both ends of the inner wall of the outer ring. The gap between two limiting bosses is greater than the length of the needle rollers. The inner diameter of the limiting bosses is greater than the diameter of the rotating shaft and less than the sum of the diameter of the rotating shaft and twice the diameter of the needle rollers.

2. The piston according to claim 1, characterized in that: The outer ring has inclined surfaces on both sides.

3. The piston according to claim 1, characterized in that: A clearance groove is provided at the connection between the limiting boss and the inner wall of the outer ring.

4. The piston according to claim 1, characterized in that: Washers are provided at both ends of the needle roller, and the washers are rotatably fitted onto the rotating shaft.

5. The piston according to claim 4, characterized in that: The outer diameter of the washer does not exceed the inner diameter of the limiting boss.

6. The piston according to claim 4, characterized in that: The thickness of the washer is less than the thickness of the limiting boss.

7. The piston according to claim 1, characterized in that: The piston body has a flow channel along its axial direction that connects to the roller groove.

8. The piston according to claim 1, characterized in that: The piston body has an annular sealing groove recessed on its circumferential surface.

9. A door closer, characterized in that: Includes the piston as described in any one of claims 1 to 8.

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